In the International Study of Kidney Disease in Children 24 participating clinics in 12 countries throughout the world are conducting clinical surveys and therapeutic trials on major kidney diseases in children. Trials in progress include (1) the effect of cyclophosphamide in patients with (a) focal segmental sclerosis and (b) anaphylactoid purpura; (2) the effect of prednisone in patients with (a) minimal change nephrotic syndrome and (b) membranoproliferative glomerulonephritis; (3) imuran in patients with severe lupus nephritis. Clinical surveys are being conducted on the natural history of patients with (1) the nephrotic syndrome; (2) recurrent hematuria; (3) familial nephritis; and (4) membranous nephropathy. An index of all patients with kidney disease seen in the participating clinics has been established to define populations available for other studies. BIBLIOGRAPHIC REFERENCES: Barnett, H.L.: The natural and treatment history of glomerular diseases in children - What can we learn from international cooperative studies? A report of the International Study of Kidney Disease in Children. Proceedings of the 6th International Congress of Nephrology, Florence, Basel: Karger, 1976, p. 470.